while( my( $epoch, $wanted ) = each %date_pairs ){
    use Time::Piece qw/ localtime gmtime /;
    use Date::Language;
    my $tp  = gmtime( $epoch );
    $tp = $tp->add_years( 31 );
    my $lang = Date::Language->new('German');
    my $got = $lang->strftime("%A, %d.%m.%Y - %H:%M:%S", $tp );
    print "$got\n$wanted\n\n";
}